Winter 2021-22 Thoughts

October 27th, 2021

About this time each fall people start asking me “What this winter will be like?” or “I’ve heard it’s going to be a bad winter!“.  Actually sometimes they start asking in August!  For the record, I’ve NEVER had a person say “I’ve heard it’s going to be an easy winter“.  Apparently most of us are quite cynical and expect the worst. 

I don’t put out a “winter forecast”.  That’s because seasonal/climate forecasting has a long way to go before we say we can “forecast” a winter.  So we’ll just call it “my thoughts” for the upcoming winter since we can at least glean a few ideas by looking over some weather tidbits.  I’ve been doing this for quite a few years and it seems to work.

For those of you with a short attention span, just three points:

  1. Plan on an “active” winter this year.  The last 3 winters were quite “boring” (most of the time) for the weather professionals. Which means they were “easy winters” for regular folks (most of the time). Of course we all remember the 4 day stretch of snow/ice around Valentine’s Day right? But most of last winter was quiet weather-wise except for that event plus some flooding in mid January. The odds are tilted toward more changeable weather this winter; I expect it to be busier here at KPTV. A better chance for a windstorm, flooding, and lowland snow.  And I doubt we’ll be locked into weather patterns for weeks/months at a time.
  2. Expect at least once we’ll see some snow or freezing rain in the metro area and lowlands west of the Cascades.  I would be surprised if we get through this entire winter without measurable snow in Portland. I’d peg the chance of “sleddable” snow at about 70% some point between November 10th and March 1st. No, we have no idea when that could happen until at least 7-10 days ahead of time 
  3. Expect a good snow year in the Cascades. Good for both water next summer and skiing during the winter.  Go ahead and plan on a normal ski season with the usual variable ski conditions from week to week. I’d give this about a 70% chance of happening too. It IS possible to get a low snow year during a La Nina winter. In fact two La Ninas back in time we saw terrible ski conditions through January! Then February/March were incredible.

SUMMARY OF THE LAST 2 WINTERS

Two winters back…2019-2020  So boring…this was our 2nd consecutive “El Nino” winter. There was a real lack of Pacific storms; it was as if the jet stream just didn’t want to perform last winter.

Last winter…2020-2021 It was a surprising La Nina winter because of the mild temperatures, plus almost nothing interesting happened weather-wise until mid January! Some widespread (light-moderate) flooding showed up at that time, but then all was quiet until a 4 day blast of cold air arrived starting February 11th. That cold air was overrun by plenty of Pacific moisture which produced a snowstorm from Portland north/east and a severe ice storm from south metro down to around Albany in the Willamette Valley. Then temperatures warmed and typical (wet) winter weather resumed. We dried out dramatically in March and April, but with plenty of cool temps.

You can check out the rest of my winter recap presentation here: https://oregonams.files.wordpress.com/2021/10/mark-nelsen-winter-weather-recap-2020-2021.pdf

So much of the past 3 winter seasons have involved a lack of storminess and drier than average weather. About time for some action don’t you think? But that’s what I thought would happen this past winter too…there’s so much we still don’t know about our climate.


WHAT’S AHEAD FOR THIS WINTER?

We have entered weak/moderate “La Nina conditions” once again this fall. Models tell us most likely it’ll be a weak to moderate event through the winter. So this will be our 2nd La Nina winter.  That can give us a few hints, definitely not a forecast, but what direction our winter might be “weighted” toward.  I’ve spent some time looking at past La Nina episodes and what happened here in the Pacific Northwest.  I based all my graphics/research on a weak/moderate event.   Right now the Oceanic Nino Index (or ONI) is in the WEAK La Nina category.  

Model consensus says we’ll likely be in a WEAK-MODERATE category during this upcoming winter.  Here’s the latest plume of ocean/atmosphere models. Anything below the “-0.5” is weak La Nina, below “-1.0” is a moderate event. Strong would be “-1.5” or lower.

Typically in these winters there are 3 effects observed to varying degrees:

  1. The north Pacific jet stream tends to be more “wavy” which means there is more of a north & south component to the jet instead of travelling straight west to east
  2. There is increased tendency for blocking somewhere in the east Pacific
  3. As a result there is sometimes more interaction of the cold Canadian air to the east and Pacific moisture with the jet stream weakening dramatically at times too.

Likely effects this winter based on a moderate La Nina event:

1.  Rainfall

I think it’s unlikely that we’ll have a drought winter; but far more likely precipitation will be above average.  La Nina winters in the Pacific Northwest are dominated by a strong jet bringing frequent disturbances across the region, interspersed with sudden ridging or northerly flow.   Then it’s back to the westerly flow.  For this reason they tend to be wet.  It’s likely the #1 most noticeable event in these winters. And the chance for “wet” is much higher in northern Oregon than the southern half of the state. Although the current weather pattern this week suggests otherwise with an incredibly wet northern California very early in the season.

1a.  Flooding

This goes with the rainfall.  For obvious reasons we tend to have more flooding events in La Nina winters due to the wetter weather. Keep in mind we haven’t seen a major regional flood in 24 years. That was 1996. Previous big flood was 1964. I wouldn’t say we are “overdue”, but one of these winters it’s going to happen again.

2.  Mountain Snow

Lots of precipitation and cool weather systems = plenty of mountain snow.  This is probably the #2 most likely event.  7 out of the last 10 La Nina winters have brought above normal snow to ALL elevations in the Cascades.  Note that there CAN be a bad year; it just happened during winter 2017-18. Ouch! Check out the mid January snowpack during 2001 & 2018…

3.  Foothill Snow

This happens in some La Nina winters…significant snow to lower elevations (1,000′-2000′).  This MAY happen again if we get a succession of cold and wet systems coming in from the west and northwest.  It didn’t happen last winter, but colder than normal ocean water is poised to the west/northwest of the PACNW.

4.  Wind Storm

We are overdue for a regionwide major windstorm here in the Pacific Northwest.  The last BIG one was December 1995.  That’s 26 years ago!  14 years before that we had the major November 1981 storm.  It’s interesting that all the La Ninas from 1950 to the mid 70s had a wind gust of 60+ mph at PDX each time!  Not as frequent since that time though.

5.  Portland Snow/Ice

This one is tough.  Anyone who says a La Nina winter means lots of snow in Portland is mistaken.  Average snowfall in weak-moderate La Ninas DOES go up a bit, but not a dramatic increase.  Three La Ninas in the last 20 years have produced a major snowfall here in Portland…December 2008, January 2017, & February 2021.  I should point out that the “cool/wet” La Nina winters sometimes produce little freezing rain because we don’t get as many inversion episodes to our east, which means less east wind in the Gorge.  We need that for a good ice storm either in the Gorge OR in Portland.

ADDITIONAL THOUGHTS:

The elephant in the living room I suppose is the fact that our winters are gradually warming, and snow in Portland is more rare than it used to be when we look back more than 70+ years. Although the past couple of decades total winter snowfall seems to have stopped it’s downward plunge.  Take a look at total snow each decade since the airport observations started about 1940. Divide by 10 to get average per winter.

And downtown records that go back to the late 1800s.  The low spot in the 80s is missing some data…it should be a bit higher…

We have always been in a marginal snow climate, but now warming temps are cutting off even more of the winter snow.  Every few winters we get a good snowstorm. We all remember that event and that pops up the long-term average.  It is interesting that the last 3 decades seem to have leveled out a bit at around 4″ per winter at both downtown and PDX locations.

WHAT ELSE COULD HAVE AN EFFECT ON OUR WINTER WEATHER?

  1. Cooler Water In Eastern Pacific There is no blob of warm water in the northeast Pacific like last fall/winter. In fact much cooler than normal now.

2. Pacific Decadal Oscillation (PDO) This is directly related to the sea surface temps. Typically during a La Nina we get a negative or “cool phase” of the PDO at the same time. Last year that was not the case. But this year we seem to be in the cool phase (right side figure below). Could that make this La Nina winter behave significantly different (cooler/wetter) compared to last year? You can read up on the PDO here: https://www.climate.gov/news-features/blogs/enso/going-out-ice-cream-first-date-pacific-decadal-oscillation

This gives the general picture

3. Anthropogenic Global Warming (Climate Change) A warming globe doesn’t necessarily mean we don’t get cold air outbreaks or snow. It can also mean the usual circulations get disrupted. For example it seems to me we just aren’t getting as much storminess over the eastern Pacific the last 3-4 years. That’s just anecdotal of course. But has something shifted the past 20 years? We don’t know, although 30 years from now, we might look back and notice something did change during this period. There is still a LOT we don’t know about climate.

That wraps it up…as always we’ll see how the winter turns out…my money (again) is on “wet”, “good Cascade snow”, and at least one “snow/ice event” in the lowlands. Maybe several, but hopefully I won’t be spending too much time at the hotel right near the TV station…

WHAT OTHERS THINK

Each autumn the Oregon chapter of the American Meteorological Society puts on a “Winter Weather Conference”. It’s my favorite meeting of the year! I have been a part of this chapter my entire career. Speakers present their thoughts/outlook/forecast for the upcoming winter. The public is always invited. Last year and just this past week we gathered virtually due to the pandemic. Interested in watching? Check out my recap, plus 5 different outlooks on our Oregon AMS web page. I was especially impressed by the passion/talent the younger folks are bringing to our chapter! There is some really good information in each of these presentations. Enjoy!

Chief Meteorologist Mark Nelsen

170 Responses to Winter 2021-22 Thoughts

  1. Hank from Salem says:

    Hopefully this doesn’t take up too much space of the comments.

    Here’s a picture of all recent moderate/extreme la nina’s, ocean temperatures on Nov 8th. unfortunately I can’t do a couple of years since there was no archives.

    Unfortunately nothing for 2020-2021

    .

    2011-2012 Moderate La Nina https://coralreefwatch.noaa.gov/data3/50km/image/twiceweekly/ssta/global/2011/crw_heritage_50km_ssta_global_20111107.gif

    .

    2010-2011 Extreme La Nina

    .

    2007-2008 Extreme La Nina

    .

    1999-2000 Extreme La Nina, somewhat different map now

    .

    1998-1999 Extreme la nina

    As of right now, temperature scale is slightly different

    .

    .

    -Hank

    • Hank from Salem says:

      I guess I’ll do weak la ninas too.

      2017-2018 La nina doesn’t always mean snow

      .

      2016-2017 Weak la ninas still can have alot of snow

      .

      2008-2009, this year is also a good example, Weak la nina doesn’t always mean slightly cooler than average winter

      .

      2005-2006

      .

      2000-2001

    • Hank from Salem says:

      After looking at the other years, I think this year will be a Moderate La Nina. Also noticed there hasn’t been many Moderate la ninas lately.

  2. Andrew says:

    Both EURO and GFS indicating rain totals in the 3-4 inch range over the next week! With the lower elevation snow from this past weekend, I have to think this will introduce some flood concerns in spots. Between the rain and snow melt, that’s a lot of water. Not sure these rain numbers will actually verify but could be an awfully wet end of the week.

    • Zach says:

      The euro absolutely nuked the northern half of Oregon today. We are inside of 5 days too so it might actually happen.

      • Andrew says:

        yeah agree. The NWS forecast discussion this morning suggested the system might still go north and spare oregon from the real high rain totals. we’ll see. I’m at two inches already this month. Could be at the monthly average of 6-7 inches before halfway point. Rain totals do appear to go way down the following week. I doubt we’ll end month that ahead of our average, frankly.

      • W7ENK says:

        Not really seeing that. 4.2 inches of rainfall by end-of-run, that’s not really abnormal for November. I’d say your “nuked” anecdote is an over-exaggeration. 🤷🏼‍♂️

  3. Zach says:

    Multnomah falls is going to roar this weekend.

  4. Andy says:

    33F this morning in Albany…much colder than the forecast low.

    • W7ENK says:

      Indeed. Woke up to 34 here, a full 10 degrees cooler than forecast. Not good, because I left my peppers and tropical trees out. Any bit of frost will likely kill them!!

    • Hank from Salem says:

      33.4 low in Salem, that’s 7 below forecast!

  5. Ken in Wood Village says:

    I was right about the possibility of funnel clouds!! The thing was we had a waterspout along the Coast and a waterspout that turned into a tornado in Vancouver BC. It was a very active day yesterday and looks to be active today but not as active as yesterday.

    Looking at the models, it looks to be an active week. We should have some dry times but they will be few and far between. Some days look like they will be around average and other days below average for temps. It’s still not clear on how strong winds could be on Tuesday. I’m thinking we won’t know until tomorrow morning or afternoon. We need to watch how the storm develops on the satellite picture and observations around the state.

    Have a good Sunday and talk to you all probably tomorrow unless something happens between now and then.

    • Roland Derksen says:

      Thanks for writing about this Ken- I missed seeing it myself here , but the pictures are pretty impressive. It’s VERY rare for us to get one of these.

  6. Weatherdan says:

    Looks just like typical November slop out there to me. Too warm for snow but too cool to really enjoy being outdoors. Sure be nice to see some Winter snow. Just no zr. Should see some snow within a few weeks. Just not the next 2 or 3. Oh well the holiday season is soon to be upon us. Cheers to you all. Peace.

  7. Roland Derksen says:

    41f and a chilly rain early this afternoon. The rain has stopped now, and I’m seeing some clearing. I expect to see a pretty low snow level on the mountains.

  8. Ken in Wood Village says:

    There is a very interesting cell around Silverton and Scotts Mills. Almost looks like a tornado hook signature. I looked at the velocity and the winds are moving in different directions. I’ll keep an eye on it.

    • Hank says:

      No tornado, although when that cell passed Salem, some hail, and one lightning strike.

      • Ken in Wood Village says:

        Yea, there was a lot of rotation with that storm. I’m getting a lot of rain now. It’s been a very active day. We need to see what happens with the low on Tuesday. It looks like there are two lows but not sure what will happen. If we will see some decent winds. It looks like the low moves up close to the Coast but how strong is the question 🤔 we may not know until Monday night.

  9. Andrew says:

    GFS still clinging to a fairly potent low riding up the coast around Tuesday. By looks of it, would be strongest winds for both coast and valley during this streak of active weather. EURO has systems splitting with the strongest going well north towards eastern part of vancouver island really going nowhere us. Would hardly even be breezy if that verifies. After that, the big story later next week appears to be rain, if models are to be believed. A potential atmospheric river takes shape around the weekend and another wet system follows that – both seem to be generating tropical energy. This is why both the GFS and EURO continue to hold on to around 4 inches of rain over next two weeks or so, with some ensemble members suggesting much higher totals. If this comes to fruition I suspect we’ll start talking about some minor flooding concerns in the standard spots. That’s not terribly atypical for this season but perhaps a little earlier than normal. Active pattern continues but agree with those other commenters that there is no immediate indication of a remarkable wind event. GFS comes closest and we all know where that leads us. But still enough going on to keep an eye on things. A predictable, boring pattern this is certainly not. Just had a very strong storm cell come through right over my neighborhood in SE Portland with hail, thunder, lightning and some very strong wind gusts. Sun is out now. In fact, that was first rumble of thunder i recall hearing all year if you can believe that! nothing here throughout the spring and summer.

    • Andrew says:

      I should note that i’m mainly looking at the deterministic forecast model, which I know is hardly accurate outside of a few days. I just struggle making sense of ensembles sometimes when the dispersion of outcomes is so large. I did want to note, many ensemble members for both GFS and EURO are not on board with an unusually wet second half of next week and into weekend. I think that’s one where it’s just too soon to know where the ridge will set up. But there appears to be a lot of energy to tap into, should the conditions line up.

  10. Ken in Wood Village says:

    These showers and thunderstorms are getting intense and it’s not even noon. The cloud formation are interesting too. I’m thinking there could be a chance of a funnel cloud and maybe a severe thunderstorm warning later if these showers get stronger later 🤔⛈

  11. yigablademaster says:

    I seriously wish Mark would allow a way to report bad comments that call people nasty names so they can be screened/filtered. Then this won’t become a Reddit circle jerk if you’ve been there you’d know what I mean.

    • Jake says:

      Well the real trouble is Mark’s blog here is no longer associated with KPTV so it largely is not administered.

      So you get people on here that make personal attacks when they have nothing of substance or presidency to say. Partially why I’ve moved on from this blog and mostly just lurk now and this will be the last blog post I comment in.

      Just not worth my time with me largely moving out of the region.

  12. Ken in Wood Village says:

    Just looked at the 00Z Euro run (I just look at a report total not the actual run) and it shows 5 inches of snow for Troutdale on Sunday morning 😳 it also shows a low temperature of 34 degrees 🤔 I very much doubt this is going to happen but if it does, we have some serious issues either with the model or the atmosphere 🤣 because I just don’t see the right set-up for snow 😒🌨❄

    • yigablademaster says:

      Exactly Ken. Almost every November this BS happens where they say ‘It’s going to be 38F and wet snow!’ and of course without the actual cold air it doesn’t happen!

  13. tim says:

    Based on the 00z gfs we got our miracle since western WA or western OR will not be getting a big blow next week via cliff mass recent post about potential wind storm, sure things could change but I doubt it.

  14. Ken in Wood Village says:

    It’s raining really hard here right now. I think the cooler air is filtering in. I believe we have a decent chance to have thunderstorms tomorrow ⛈ I’m off to bed 🛌 😴 🤗

  15. Jake says:

    Ensembles are starting to catch on that it is November and that the potential for some serious rainfall is upon us. A very notable spike upward in the graphical data. Still a week away but the tally is over 7 inches now.

    A lot of people don’t know that Portland’s water supply via the Bull Run Watershed is actually derived solely from rainfall. There’s mountain range that blocks snow melt from Mt. Hood. We need this despite the flood potentials.

    Another cool feature is that sometimes this snow melt comes down into the valley and gorge in the form of springs which include some of the waterfalls in the Columbia River Gorge.

    • Joshua Lake Oswego says:

      Models are trending a lot drier actually. The 12z Euro ensemble mean is just over 4’’ over the next 2 weeks. Most likely, we will end up way short of that. Closer to 2’’ or less is my estimate. In fact, the first half of November could end up drier than normal.

  16. Andrew says:

    Euro shows a low running up our coast from the south Tuesday that “could” actually generate a warning inland and produce enough wind to knock power out in areas. GFS for now keeps it to our south. That’s the one i’ll be watching.

    These rain totals seem consistently inflated in the long term. models have done considerably better on low tracks and wind speeds.

    • Anonymous says:

      Let’s hope it misses us. I’m over losing power for a long time after dealing with it during the ice storm in February.

      • Joshua Lake Oswego says:

        Don’t worry, it will miss us by hundreds of miles. It’s two separate weaker lows now anyway. Non-event.

  17. W7ENK says:

    So, is the wind ever going to pick up, or is this thing just one giant bust? Been mostly calm here in Milwaukie all day, had some light breezes a couple hours ago, but nothing to strip down the leaves…

    I hope that wasn’t it!!

  18. Andrew says:

    Suns coming out…that usually means strongest winds.

  19. Zach says:

    12z gfs put 7″ in portland over the forecast period.

    • Anonymous says:

      Euro was trying to do the same yesterday for the 10-day period (along with snow lol). It’s backed off some – as predicted – and I expect the numbers to go down further. That said, it seems we’re definitely getting a series of consistent downpours, so those rain totals will look impressive regardless

      • Anonymous says:

        Numbers went down again on both GFS and Euro

        • Zach says:

          Nope the 18z GFS upped the ante. About 8″ in the metro. Granted its the 18z so pretty meaningless.

        • Anonymous says:

          I’m looking at the next 10 days, not the entire GFS run which goes out to the 20th. Anything after 7 days really is pure fiction

    • Jake says:

      Ensembles have consistently been trying to climb:

      https://meteor.geol.iastate.edu/~ckarsten/bufkit/image_loader.phtml?site=kttd

      Also noting the ensembles putting some chilly Fall weather in our near future which now reasonably shows amazing snowpack.

      At this rate they’ll need a mineshaft elevator for the front door at Mt. Hood Timberline Lodge lol!

      • Jake says:

        I joke of course, but probably by 2nd week of December if this keeps they’ll have the classic cave around the door.

  20. yigablademaster says:

    Okay folks it’s getting gusty now and here’s your (censored) windy weather event you’ve been waiting for since the ice storm and yet NO comments! What the hell? 😲🤔

  21. Ken in Wood Village says:

    I’m looking at my radar and some of the cells are showing rotation. Keep your eyes to the skies, you could see a funnel cloud or two. 🌪⛈🌧

  22. Ken in Wood Village says:

    I’ve been up since 3am. I normally try and get up at 4am because getting up any earlier means I have a long day…lol. Since I got up early, I decided to look at a lot of things. The one thing I was having a hard time finding was the Low. I think there are two Low’s and the models are not really picking up the second Low. When I look at the models, they put a Low up next to Vancouver Island. But the Secondary Low is much further South (I’m guessing its somewhere around 43.04°N 129.15°W. I’m not sure how strong this Low but I was looking at the Buoy information around were the low is and some are reporting winds around 46mph (that’s a rough estimate). Since the models are not really picking up the Secondary Low, I have no clue on were it’s going. It’s still moving East-Northeast. Not sure if it will go South of Portland or move North.

    I did notice that Crown Point had a gust of wind of 84 mph at 11:50pm last night.

    Also kind of noticing the showers we are having right now are the kind thunderstorms build into. With all the wind, I would think there is a possibility of maybe a funnel cloud or two.

    One side note, if we were in the middle of December and we had cold air in the Gorge, this would have been a classic set up for a snowstorm. I noticed it yesterday but kept forgetting to post my thoughts about it…lol.

    Have a good day and we’ll see if we get some decent winds!!

    • Hank says:

      Yeah, the 2nd low seems strong, I noticed that last night, I’m somewhat confused from how no weather models are showing it, even though it seems like a somewhat strong low.

      • yigablademaster says:

        I trust models only 50 percent of the time. Garbage in = Garbage out if you know even the basics of programming it isn’t a confusing concept.

  23. Andrew says:

    The models aren’t really suggesting any noteworthy storms for Portland area, just confirming an active pattern. But then again, the last cyclone garnered a lot of media attention and it was really nowhere near us. These systems appear more on the right track, just not nearly as strong. Good string of windy days for coast that’s for sure!

    • yigablademaster says:

      I don’t go by what the models ‘suggest’ I go by long term and short term climate effects and ocean temps. There are many parameters the models do NOT take account for and as long as they don’t take account for they will have a high fail rate when change occurs.

  24. Hank says:


    https://ibb.co/7WnqGzW
    Hopefully one of these works. But if it doesn’t click on the 2nd ibb link. Thats where the storm is now

    Hopefully this works
    And this is where it was forecasted to be by now, from a forecast a few hours ago.

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